The present invention relates to solar screens, awnings and the like, and more particularly, to a roller tube for a solar screen or similar material including an integral slot that maintains a circular inside diameter for mounting drive motors.
Roller shade systems make use of flexible shades supported by elongated roller tubes. The roller tube, typically made from aluminum or steel, is rotatably supported and provides support for the flexible shade on the roller tube. Roller shades include manual shades having spring driven roller tubes and motorized shades having drive motors engaging the roller tube to rotatingly drive the tube. The drive motors for motorized shades include externally mounted motors engaging an end of the roller tube and internal motors that are received within an interior defined by the tube.
Conventional roller shades have support systems that engage the opposite ends of the roller tube to provide the rotatable support that is required for winding and unwinding of the flexible shade. The support system includes a drive end support assembly having a coupler engaging the open end of the tube for rotation. The coupler is adapted to receive the drive shaft of a motor such that rotation of the drive shaft is transferred to the coupler for rotation of the tube. The motor is secured to a bracket for attachment of the roller shade system to the wall or ceiling of a structure, for example. A coupler engaging an opposite end of the roller tube could receive a motor drive shaft or, alternatively, could receive a rotatably supported shaft of an idler assembly.
In certain roller tube arrangements, the drive motor is inserted into the roller tube body. The drive motor includes a substantially circular outer shape that snuggly fits into the inside diameter of the cylinder shaped roller tube.
The roller tube serves to support and fix the screen material, such that the screen can wind and unwind in a smooth manner. It is important in the attachment of the screen to the roller tube outside diameter to align the screen perpendicular to the axis of rotation of the roller tube. If the screen is out-of-square alignment with the roller tube, then the screen will wind and unwind in an uneven manner. A screen that is out of alignment can bind and create unsightly wrinkles along the surface of the solar screen/awning that is undesirable.
The prior art roller tube designs have attempted to solve the problem of attachment of the screen to the roller tube in various ways. A common prior art technique of attachment is to use carpet tape along the outer surface of the roller tube. The carpet tape adheres to both the roller tube and the screen. The carpet tape technique can result in a time consuming process that can yield screens that are out of alignment.
Another prior art technique of attachment is to form a groove in the roller tube exterior for insertion of the screen material. The groove acts to align the roller tube material sufficiently. This technique may include a separate bar that can clamp onto and or into the groove in the roller tube such that the screen material is clamped between the bar and the groove.
A substantial drawback of the prior art roller tube and groove techniques is that the groove formed in the roller tube creates a protrusion that bulges into the inside diameter of the roller tube. The protrusion into the prior art roller tubes inhibits the insertion of a drive motor into the roller tube. With the protrusion, the roller tube cannot accept the substantially circular drive motor without modification to the drive motor housing. Modification of the drive motor makes the installation more costly and less practical.
Other prior art attempts maintaining the circular inside diameter involve the use of additional clamping bars to the exterior of the roller tube. These techniques lose the advantage of the groove to provide a true orthogonal baseline to align the screen material, and create a bump in the material rolled around the tube.
It would be advantageous to provide a method and an apparatus to ensure that roller tube and screen material are in proper orthogonal alignment while being able to utilize interior drive motors without the added costs and complexity of the prior art systems. The present invention provides the aforementioned and other advantages.
What is needed in the art is a roller tube having an external slot for mounting the screen without forming protrusions in the roller tube interior.